This invention relates to shutter devices for photographic printers, and more particularly to a shutter device which has a high response characteristic and is uniform in operation.
A photographic printer employs a shutter device for controlling printing exposure times. A conventional shutter device of this type has a shutter paddle which is driven by a rotary solenoid. In the shutter device, when current is applied to the rotary solenoid, the shutter paddle, which is in the printing optical path, is caused to move out of the printing optical path to start the exposure operation, and when the application of current is interrupted, the shutter paddle is caused to move into the printing optical path again by the force of a spring, to end the exposure operation.
In this shutter device, the shutter paddle is returned by a spring as described above. Therefore, the shutter device suffers from serious problems in that it has a low response characteristic and is low in reliability in operation. Furthermore, since the optical path is opened and closed by reciprocating one shutter paddle, the shutter device is disadvantageous in that the amount of exposure given the exposure surface is not always uniform.